Tonnes of perfectly good food are thrown away in the UK every year. Why, asks Hugh Fearnley-Whittingstall.

I've witnessed some pretty grim scenes in the food business down the years - appalling conditions in the poultry industry, crazy EU fishing laws, all kinds of greed and folly.

Root vegetables may be a touch harder to feel for than chickens or fish. But watching 20 tonnes of freshly dug parsnips consigned to the rubbish heap in a Norfolk farmyard - purely because they didn't look pretty enough - is still one of the most shocking things I've ever seen.

That's not just a few sackfuls of parsnips, it's not a skip-load. It's a colossal mountain of them - enough to fill nearly 300 shopping trolleys. And, more importantly perhaps, to feed 100,000 people with a generous portion of roast parsnips.

That was just one week's wastage. So multiply by the 40 or so weeks of parsnip season (September-May) to get the full annual figure - four million parsnip portions that could, but won't, get eaten.